Adjustable mask



FIG. 1 is a perspective view of an adjustable mask, showing my new design in an unadjusted configuration;

FIG. 2 is a left side elevation view thereof;

FIG. 3 is a right side elevation view thereof;

FIG. 4 is a rear elevation view thereof;

FIG. 5 is a front elevation view thereof;

FIG. 6 is a top plan view thereof; and

FIG. 7 is a bottom plan view thereof.

FIG. 8 is a perspective view thereof, shown in an adjusted configuration;

FIG. 9 is a left side elevation view thereof; and,

FIG. 10 is a top plan view thereof. 

CLAIM The ornamental design for an adjustable mask, as shown and described. 